The distribution of network processing load within a networking device, such as a router or switch, is commonly fixed and largely determined by the architecture of the networking device. Depending on the manufacturer, for example, forwarding decisions and other packet processing is generally predetermined to be performed at either ingress or egress. As a result of the inherent asymmetric processing loads and asymmetric traffic patterns, the network processing load at the ingress point is rarely equal to the network processing load at the egress point in fact, the disparity in processing load between the ingress and egress is often so great that it is common for a processor at one side of the switch to struggle while a processor on the other side of the switch remains nearly idle.
Although some networking devices may share some processing load with other networking devices to balance the processing effort across the available processors, these schemes cannot dynamically balance the packet processing operations because: (a) network processing is typically accomplished by hard-wired application-specific integrated circuit (ASIC) devices, which are very good at repetitive tasks but generally lack the intelligence to alter the distribution of tasks dynamically; (b) network clusters employing distributed processing are designed to handle a set of large and fixed tasks, but are relatively slow and unsuitable for packet processing; and (c) most networking devices are simply over-engineered to accommodate the worst possible load with no consideration given to the excess computing capacity wasted at a system level.
There is therefore a need for a network switching device that can monitor for packet processing load imbalances and dynamically distribute the load between the ingress and egress processors to minimize the imbalance.